Mechanical fog generator



Jan. 26, 1954 w. J. BESLER MECHANICAL FOG GENERATOR Filed Nov. 15, 1947 3 Sheets-Sheet l INVENTOR.

Alla/nay Jan. 26, 1954 w. J. BESLER 2,667,459

MECHANICAL FOG GENERAT61 Filed Nov. 13, 1947 3 Sheets-Sheet 2 a u o 16 2' m a VJ:-

INVENTOR.

BY W My Alfarne y Jan. 26, 1954 w. J. BESLER 2,667,459

MECHANICAL FOG GENERATOR Filed Nov. 15, 1947 3 Sheets$heet 3 INVENTOR. WM;- M

BY M M A/IOrng/ Patented Jan. 26, 1954 UNITED STATES idl'ENT OFFICE 4 Claims.

There has been an increasing demand for smaller, portable units for making artificial fog and the present invention represents further improvements upon my two co-pending applications, the first of which is serially numbered 532,292, filed, February 21, 19%, which issued as Patent Number 2,432,372 on December 9, 1947, this application being a continuation in part thereof, and the second of which was filed November 12, 1947, and is serially numbered 785,351 now Patent No. 2,630,412.

Among the objects of the present invention is the creation of a device which, using steam as a vehicle, will produce a thick, impenetrable, obscuring fog for military purposes in covering military objects and movements.

similarly it is an object of the present invention to produce such a fog but which at the same time may be breathed for extended periods by humans and animals without injurious affects.

Another object of the present invention is to produce an artificial fog which is non-combustible even though produced from a combustible source material. A still further object of the present invention is to provide a quick acting, compact machine for generating a maximum volume of fog in a minimum period of time and with a minimum of supervision.

It is also an object of the invention to provide 'a device which has peace time uses and which can be operated as an insecticide disseminator or as an artificial aerosol for the protection and treatment of crops, vegetation and the like and for the extermination of harmful insects.

A further object is the coordination of the fuel supply of the fog oil supply and the water supply to the motive means, and the utilization of the products of combustion from the motive means, all in a most efficient manner.

Further objects are to provide a construction of maximum simplicity, economy and ease of assembly and disassembly and such further objects, advantages and capabilities as will fully appear and as are inherently possessed by the device and invention described herein.

The invention further resides in the combination, construction and arrangement of parts illus trated in the accompanying drawings, and while there is shown therein a preferred embodiment it is to be understood that the same is illustrative of the invention and that the invention is capable of modification and other uses and com prehends other details of construction without departing from the spirit thereof or the scope of the appended claims.

In the three sheets of drawings:

Figure 1 is a side elevation from the blower side of a mechanical fog generator constructed in accordance with this invention, a portion of the generator being broken away and shown in vertical section.

Figure 2 is a plan view from above of the same.

Figure 3 is a diagrammatic perspective of the same showing the liquid systems, the motor assembly being omitted.

Figure 4. is an end elevation of the assembled device from the systems end.

Figure 5 is an enlarged detail in vertical section of the thermostatic fuel control valve.

Figure 6 is an enlarged detail in vertical section of the feed water regulator.

Figure '2 is an enlarged vertical section of the manual fog oil valve.

The detailed structure of the device of the present invention shown in the drawings is best understood by reference to Figures 1 and 3. Essentially it is divided into three component organizations, the first of which is the base Hi, the second of which is the steam generator H, and the third of which is the group of systems arranged on the base at the opposite end from the steam generator II.

The base It! is preferably a tank which is divided into two non-communicating compartments by the wall l2. When used as a fog machine as here described, the water tank is compartment l4 and the fuel tank is compartment !5. Each tank has its separate filling spout and cap, the one for water being designated l6 and the one for the fuel, l1. While the drawings indicate that the base Ii) may be one tank divided into individual compartments, it is obvious that it also may be built up by welding or otherwise securing two or more tanks together into an integral unit.

Since portability is one of the important features of the present device, the base it is provided with brackets i8 at eachof the four corners thereof near the top through which handles 20 and 2! are slideably mounted. For purposes of structural strength the base may be provided with reinforcing ribs 22 at spaced intervals.

The generator H has a cylindrical air casing 23, the lower edge of which is welded or secured in any other suitable manner to the top 24 of the base It. Above the air casing 23 is a flue pan 25. The meeting edges of the flue pan and the air casing are flanged outwardly and held together by girth band 26, the ends of which are drawn together by the turn buckle or clamp bolt 21. The flue pan is provided with an offset outlet 28 for the escape of the waste products of combustion from the boiler. The interior wall of the air casing 23 is insulated as at 3B and also at the bottom as at 3|. The cylindrical combustion chamber 32 has a vertical wall 33 spaced from the insulation 36 to provide air space 3s. The combustion chamber has a bottom secured to the vertical wall thereof having a central opening 35. The opening 38 leads to a pri-- mary combustion chamber 3'! which is cylindrical in shape having a vertical wall 38 and a bottom All which depend from and are secured to the bottom 35 of the combustion chamber 32.. The burner assembly 4! passes through the insulated air casing wall and into the primary combustion chamber 3?, the same being mounted upon the burner flange :12 for ease of assembly and disassembly. I'he burner assembly includes a spark plug 43 which provides the ignition for a vaporizing fuel. Combustion :air is supplied by a blower (not shown) contained within the blower housing all having a screened air intake 45. The blower delivers combustion air tangentially through a duct leading from the blower housing 44 through the insulated air casing 36 into the air space 34. From there the air passes through a series of louvers 46 in the vertical wall 38 of the primary combustion chamber 3?. The products of combustion pass upwardly through the opening 36 through the chamber 32 where combustion is completed. The hot combustion gases pass upwardly through the spaced coils i? to 52 and are dissipated to atmosphere through outlet 28 in flue pan 25. 'It is to be noted that the outlet 28 is offset and that the flue gases are defiected by the baffle 53. This is done so that the generator has better efficiency characteristics and also to prevent, to a very large measure, the glow resulting from the heating of the'metal.

The vapor generating surface of the boiler consists of a series of flat spiraled or pancake coils 41 to 52 interconnected to form a continuous passage from inlet to outlet. The inlet passage 5% leads directly to the uppermost coil 41 and the flow is progressively downward or in counterflow relationship with respect to the combustion gases. This series of coils is supported upon an inward annular indentation 55 in the wall 33, the curvature of the spiral being such at this point that it does not show the lowermost coil resting thereon in Figure 1.

The lowermost coil 52 discharges at 56 into a horizontal of tubing 57 which contains the thermostatic tube 58. The flow then goes upwardly substantially on the axis of the boiler through discharge tube 69, out through the due pan 25 to the manifold B! which is provided with a series of jets 52 through which the generated vapor and its entrained material is released and expanded into a heavy fog into the surrounding atmosphere, all as is more fully explained hereinafter.

A gasoline engine 63 is used as the means for driving all of the systems of the device. The blower fan within housing 54 is driven directly from the shaft of the engine. The shaft also has a sprocket thereon for driving the sprocket chain 55 encircling the sprocket 65 for driving the pump 55. When the device is used as here shown for the making and dissemination of fog or a fine aerosol, five systems are involved in its operation.

The gasoline system This system supplies fuel to the engine 63 and torll.

to the burner assembly 4!. When the engine 63 is started the gasoline pump 5'! which is an in tegral part of the engine, produces suction drawing gasoline from the tank I5 through line 88 in which is interposed a strainer 1!]. Flow of the gasoline or other vaporizing fuel after passing through the pump 67 is divided in its flow in two directions. One portion H goes to the engine carburetor (not shown) and the other goes via line 12 to the thermostatic fuel valve .73. When the unit is cold the thermostatic fuel valve is open permitting free passage of the fuel to line 14 leading to the fuel control valve 15 which is closed until the burner 45 is to be started. When the burner fuel valve 15 is open the vaporizing fuel flows through a control orifice 16 which limits the amount of fuel for full fire and passes in line I? to the burner assembly 4| where it is vaporized and mixed with air and ignited by the spark plug 43 to produce a long torch-like flame within the primary combustion chamber 31. It will be observed at this point that the line it passes inside of pipe 5,8 which conducts the ex haust from the engine 63 to the burner assembly where it not only warms the burner, insuring prompt starting in cold weather, but also warms the fuel on its way to the burner assembly.

The water system When the engine is started a fog oil-water pump produces suction which draws water from tank i i up through line 86 in which is interposed strainer 8!, to the feed water regulator 82 (see Figure 6). The water enters through .a .restricted orifice 83 and leaves through needle valve 84. The feed water regulator comprises a body member 85 with a flanged cap .85. A flexible diaphragm 81 is held between the body member and the cap to form a pressure and liquid-tight gasket around its periphery. Plates .38 and t9 reinforce the central portion of the diaphragm. The needle valve 34 is fixed in the plates in the center of the diaphragm in registry with the valve seat adjacent the outlet 9i leading to the pump 66. The valve 84 is normally held open by the coil spring 92. The needle valve is provided with an adjusting nut 93. Cap member this vented to the atmosphere through vent 9 3. A petcock is provided in the valve housing 85 as a means for draining the same should this be required.

As stated above the valve 36 is normally held open by the spring 92. However, when the engine has been started and the suction increased to one pound per square inch the diaphragm is acted upon by the suction to compress the spring, partly closing the valve 84, thus preventing an over supply of water by maintaining a constant suction on the regulator body. In other words the regulator maintains a uniform pressure drop across the orifice 83 thereby maintaining a uniform water delivery. The water so delivered enters the line 96 to the pump 67 through the three-way valve 91.

The fog oil system This system supplies the fog oil to the genera- The fog oil is introduced into the system by means of the fog oil-Water pump 66. Usually the fog oil or other material to be put through the generator is supplied in separate drums or tanks. The device is supplied with flexible hose 9B for introduction into the source of fog oil supply and the suction of the pump forces it through the fog oil filter Jill! and f the threeway valve 91 is in the on orfoggi-ng position. the fog oil will be delivered "to line '96 where it mixes with water coming from the feed water regulator 82. The mixing usually takes place before passing through the pump 66 but in any event thorough mixing is completed by the pump which delivers the mixture to line I III.

The electric system The electrical system consists of a magneto driven by the engine 63 which supplies current not only for the spark plug on the engine but also to the spark plug 43 in the burner for ignition. A single switch (not shown) on the engine housing will cut off the spark in both instances.

The combustion air system As stated before, this system draws air from the outside through the air inlet 45 of the fan casing 44 and delivers it to the air space 34 inside the air casing 23.

The operation of the device is as follows. The handle I02 on the three-way valve 9'! is placed in the vertical position. (Horizontal position in Figure '7 is in the direction of the arrow.) The engine 63 is then started and immediately thereon the systems begin to function. The suction of pump 66 delivers water to the feed water regu lator 82 in the manner previously described. However, since the valve 66 is in the vertical or off position, water will pass directly through this valve via transverse passage S03 and into the pump via line 96. Water is immediately supplied to the coils through line I0! which joins with inlet line 54. The vaporizing fuel is delivered by pump 61 to the engine carburetor and the thermostatic fuel control valve I3. The blower also starts and air is supplied to the generator for combustion purposes as described above. The motor 63 is run for a few moments so that the exhaust gases will warm the supply line 11 and the burner assembly 4| before the fuel is manually turned on at valve I5. The exhaust gases from the engine are led through the line 78 to a point beneath the burner assembly. The heat of the exhaust gases assists in the vaporizing of the fuel. The exhaust gases do not however mix with the gasoline or vapor in the burner assembly. Within a few seconds after the engine is started the burner valve 75 may be opened permitting the vaporizing fuel to pass through the restricted orifice I6 to the burner assembly 4| through line 11.

As soon as the burner fuel valve I5 is opened, fire will come on in the combustion chamber 31 at the full rate for the operation of the device.

As soon as the generator has come up to opcrating temperature, the fire will automatically reduce itself to low fire which will be maintained during the entire operation. The fog oil may now be introduced into the system by moving the handle I02 on valve 9! to the horizontal or on position shown in Figures 1, 2, 3, and 4. In Figure 7 the valve is shown in the on position. In this position the pump 66 pumps fog oil through the flexible tubes 98 through the filter I00 through the fog oil intake I05 in the valve through the lateral passage I05 to the line 96. Since the valve 91 is of the tapered plug type, the upper proportion of water measured by the feed water regulator is delivered through the valve by by-pass groove I06 where it mixes with the fog oil in the line 96 on the way to the pump. v

The mixture of fog oil and water is delivered to the first of the coils, 41, in the generator through lines IM and 54 and passes successively through the coils 41, 48, 50,5I and 52 in substan' tially a counter-flow path with respect to the products of combustion from the combustion chamber 32. In these coils the Water is quickly transferred to superheated steam and vaporizes some of the oil. The flow then passes from coil 52 where it discharges at 56 into the straight length of tube 51 containing the thermostatic MM 58. From thence it passes upwardly hrough outlet tube 60 to the manifold 6I where -t is released to atmosphere through the nozzle 62. The result is an immediate, dense persistent and covering fog which is neither inflammable nor injurious to respiration.

Thermostatic control valve I3 is provided to control the supply of fuel to the burner assembly 4| in order to maintain automatically the proper temperature at the outlet for the fog making fluid. This valve has a fuel inlet H0 and a fuel outlet I I I closed by the diaphragm I I2 under spring pressure on the valve head H4 above the outlet. The valve head H4 has its stem H5 in contact with a bell crank H6 which is pivoted at II! and depressed by the spring II8 attached to the surrounding case I20. The arm I2I of bell crank IIB bears against the thermosensitive rod I 22 which extends through and is secured in the tube 58. It is apparent by adjusting the length of the stem II5 the closing of the fuel valve can be accomplished for any temperature required. As stated above, this valve is open at the start so that vaporizing fuel is free to pass therethrough. However, as the temperature approaches the setting only enough fuel will pass through the valve 13 to maintain the tempera ture of the setting. The unit comes up to temperature very quickly and as the tube 58 expands with the heat it will expand more rapidly than the thermostatic element I 22 increasing the tension of the spring II8 on the stem H5. In this manner the flow of vaporizing fuel through the valve I3 is reduced and stopped altogether when the temperature has reached the temperature of the setting. When the temperature drops the tension on spring I I 8 is reduced opening the valve 13 and reestablishing fire in the burner. In this manner automatic control is maintained for the entire operation. When the device is used for fogging purposes the thermostatic control valve is set to close at 900 F. which means that the valve 13 will open and remain open just enough to permit passage of fuel to maintain the temperature at this setting.

The fog oil used for fogging purposes and for fine aerosol is a highly refined lubricating oil or any oil which responds to the Chemical Warfare Service code designation SGF.

At a pump speed of approximately 1,000 R. P. M. and a ratio of water to fog oil of 1:8.5 or 1:9 with an operating temperature of 900 F. the device will produce fog having a particle size of from .1 to .3 micron radius in less than one minute from a cold start.

The peace time uses of the device normally re quire a larger particle size in order to give better local control of the travel of the aerosol. It has been discovered that the size of the entrained particle released with the steam vehicle from the nozzle jets 62 is a function of the operating temperature of the device. Thus aerosols having a particle size from 2 to 10 microns radius for example, are obtained by operating the device at temperatures ranging between 450 to 550 F.

As is amply demonstrated by the foregoing the function of the water system in the operation of the device is. to. provide the. steam vehicle for the dissemination, of entrained: particles. If the machine. is to be used for: the dissemination of insecticides, the insecticide. emulsion already contains the proper proportion of water. Hence itis not necessary'to use the water system which may be;- either disconnected. or removed. entirely without altering the, function or operation of the device. No matter how it is; used, it is the steam produced by the generator which is the vehicle for securing an aerosolor: fog. If fog is being made the result will be a dense, persistent, covering, white fog or aerosol. On the other hand if an insecticide emulsion. is being put through the device the result; will be a thick, cloud-like fog which carries the lethal dosage to every portion of the; trees or; crops. or whatever may be the object of the'treatment. It: should be noted that in, use the. manifold 6|; may be mounted with. a. universal joint and aimed in any direction desired;

1.. A. device, for producing an artificial aerosol comprising in combination'a. vapor generatorineluding a. fluid circuit therein arranged for counterflow with respect to-heat from the burner; and a. burner.- for: a vaporizing fuel, auxiliaries including a constant: speedv engine for simultaneously driving several. units comprising a pump for; supplying the vaporizing; fuel to the engine andithe burner, a. blower for supplying combustion air to the'generaton. anda pump for supplying. operating: fiuidf to said fluid. circuit, a water regulating valve communicating with the suction side of: said pump and: operable to supply water thereto in response to the negative pressure thereof: to; maintain delivery of a constant ratio of operating fluid and; water, and restricted orifices for releasing. the vapor and entrained particies of operating; fluid at the outlet end of the fluid circuit on the outside of the generator to produce an artificial: aerosol;

2. A device: for producing an artificial fogcomprising in combinationa vapor generator includinga fluid circuit therein for vaporizing the operating fluid arranged for counterflow with respect: to heat from: the burner, and; a burner for a vaporizing fuel, auxiliaries including a constant speed engine for simultaneously driving several units comprising a pump for supplying the vaporizing fuel to the engine and the burner, a blower for supplying combustion air to the generator, and a pump for supplying the operating fluid comprising a mixture of. water and fog oil in a predetermined ratio to said fluid circuit, a water regulating valve communicating with the suction side of said pump and operable to supply water thereto in response to the negative pressure thereof to maintain delivery of a constant ratio. of. operating fluid and water, thermostatic means within and adjacent the outlet end of said fluid circuit for controlling the flow of vaporizing fuel to said burner, and nozzles for releasing the vapor and entrained particles of operating fluid at the. outlet end of the fluid circuit on the outside of the,- generator to produce. an artificial fog.

3'. A portable device for producing an artificial R we.

fog comprising incombination. a. hate. havin noncommunieatingcompartments, I a boiler. including afluid circuit anda. burner u i v iwrib ing fuel mounted toward one endof said base, ignition means for said burner, an internal combustion engine for simultaneously driving a series of units, all mounted toward the opposite end of said base, comprising a pump for supply ing a vaporizing fuel from one of said compartments to said engine and said burner, a pump-tor supplying the operating fluid. comprising fog oil and water to said fluid circuit, and. a normally open water regulator interposed between a water compartment and said pump and responsive to the negative pressure thereof to deliver water in ratio to the volume of fog oil; delivered thereby maintaining a constant mixture of; oper t n fluid, manual means for setting the maximum operating outlet temperature for said. fluid circuit, and thermostatic means; "for automaticall shutting off the. supply of vaporizing fuel. tot-he burner when the said set temperature is reached, and maintaining a now of said. fuel when; the temperature is below said setting.

4. A portable deviceior producing: an artificial aerosol comprising in combination a base having noncommunicating compartments for water; and fuel, a boiler including a. fluid circuit and; a burner using vaporizing fuel mounted: toward one end of said base, ignition. means for said burner, an internal combustion, engine for Sim-ultaneously driving a series. of units, all, mounted toward the opposite ends. of said, base, comprising a pump for supplying; a; vaporizing fuel from said fuel compartment to said engine and said; burner, a blower for supplying combustion air to the burner, a pump for supplying the vaporizing mixture comprising fog oil and water tesaid; fluid circuit, and a water regulator valve interposed between the water compartment and the suction side of said pump, having. an inlet orifice andza normally open outlet responsive to the negative pressure of said pump to deliver water in. ratio to the volume of fog oil delivered thereby maintaining a constant mixture of vaporizing mixture, nozzle means for releasing the vapor and itsientrained particles at the outlet endof said. fluid circuit outside said generator to. produce an artiflcial aerosol, manual: means for setting the maximum operating outlet temperature for said fluid circuit, and thermostaticmeans for automatically shutting off the supply of vaporizing fuel to. the burner when-- the said set temperature is reached, and maintaining a flow of said fuel when the temperature is below said setting.

WILLIAM J. BES'LER.

References Cited in the file of, this patent UNITED EE'I'ATESv PATENTS Number Name Date 2,360,178 Turpinet a-l Oct. 1'0, 1944 2,426,846 Roselund'; Sept. 2, 1947 2,428,580 Pennow' Oct. '7, 1947 2,432,372 Besler Dec. 9, 194"! 2,447,067 Hamilton Aug. 17, 1948 2,451,019 Davis Oct. 12', 1948 

1. A DEVICE FOR PRODUCING AN ARTIFICIAL AEROSOL COMPRISING IN COMBINATION A VAPOR GENERATOR INCLUDING A FLUID CIRCUIT THEREIN ARRANGED FOR COUNTERFLOW WITH RESPECT TO HEAT FROM THE BURNER, AND A BURNER FOR A VAPORIZING FUEL, AUXILIARIES INCLUDING A CONSTANT SPEED ENGINE FOR SIMULTANEOUSLY DRIVING SEVERAL UNITS COMPRISING A PUMP FOR SUPPLYING THE VAPORIZING FUEL TO THE ENGINE AND THE BURNER, A BLOWER FOR SUPPLYING COMBUSTION AIR TO THE GENERATOR, AND A PUMP FOR SUPPLYING OPERATING FLUID TO SAID FLUID CIRCUIT, A WATER REGULATING VALVE COMMUNICATING WITH THE SUCTION SIDE OF SAID PUMP AND OPERABLE TO SUPPLY WATER THERETO IN RESPONSE TO THE NAGATIVE PRESSURE THEREOF TO MAINTAIN DELIVERY OF A CONSTANT RATIO 